Bacharach's Monoxor III is a continuous sampling instrument that quickly and accurately measures levels of CO between 0 and 2,000 ppm.
Supplied with a stainless steel probe and five feet of tubing to sample CO found in flue gases of residential furnaces, combustion appliances, commercial and industrial boilers.
I needed this for one project - it is barely used. $300.
Full Specs at:
ron.flax at gmail dot Com